The present invention describes an apparatus which, when inserted into a standard manhole of any of a number of various sizes, reduces or eliminates the odors associated with sewer gases which are typically vented to the atmosphere from the manhole.
Malodorous gaseous compounds, especially sulfur-containing compounds, are especially prevalent in municipal sewer systems. These malodorous compounds include hydrogen sulfide, methyl mercaptan, organic sulfides, amines and other nitrogen containing compounds.
Activated carbon, especially an activated carbon impregnated with a reagent which is reactive toward malodorous compounds, is useful in adsorbing malodorous gaseous compounds such as those associated with sewerage. One such impregnated carbon is the NaOH/moisture impregnated carbon described in Sinha et al, U.S. Pat. No. 4,072,479 which is herein incorporated by reference.
The use of an impregnated activated carbon such as that described in Sinha et al in the adsorber of the present invention will effectively reduce or totally eliminate odors associated with sewer gases venting from manholes containing the adsorption apparatus presently described and claimed.
U.S. Pat. No. 154,645 discloses sewer ventilators which occupy about half of the area of the sewer opening so that no back pressure is maintained in the sewer. Thus, all of the sewer gas to be treated is not forced through an adsorbent bed, as required by the instant invention, by a positive sewer pressure.
U.S. Pat. No. 3,377,784 is directed to the use of portable manhole filter assemblies on transporation tanks.
U.S. Pat. No. 3,475,885 is directed to a retainer used in sewer line vent pipes to purify escaping gases.